Focal-tester for eye-lenses, &amp;c.



0'. KUEHN. FOCAL TESTER FOR EYE LENSES, 6w.

urucmou mm No.20. 1911.

. INVENTOR v 0% HZe/m/ BY ATTORNEY atented Sept. 24, 1918;

OTTO KUEI-IN,

on NEW YORK, 1v. Y.

FOCAL-TESTER FOR EYE-LENSES, 8w.

Specification of Letters Patent.

Patented Sept. 24, 1918;

Application filed December 20, 1917. Serial No. 208,018.

To all whom it may concern:

Be it known that I, OTTO KUEHN, a citizen of the United States, and a resident of the borough of Manhattan, city, county, and State of New York, have invented certain new and useful Improvements in Focal- Testers for Eye-Lenses, &c., of which the following is a specification.

The object of my invention is to afford simple but accurate means whereby the focal characteristics or peculiarities of an eye-lens may be expeditiously and conveniently ascertained from the whole or a portion thereof,-as where it is desired to reproduce a prescription when the original thereof is not readily available.

The invention consists essentially, in combination and arrangement, with a trial frame adapted to support test lenses in a manner well known in the art, of means whereby the whole or a portion of an eye-glass may be secured and held in proper relation to and upon said trial frame so that test lenses may be utilized to detect the focal structure of the eyeglass examined,-the latter in this case being tested as to requirements for reproduction in a manner similar to that in which the eye itself has heretofore been tested. In other words the requisites for the duplication or reproduction of the eye-glass are ascertained by substantially the same method by which the oculists prescription was formulated,-the eye-glass or portion thereof being substituted in lieu of the eye.

In the accompanying drawings,

Figure 1 is a front elevation of my focal testing device;

Fig. 2, a. rear view of the same;

Fig. 3, is a cross section taken upon plane of line 33, Fig. 1;

Fig. 4:, is a side elevation of one of the eye-glass clamps;

Fig. 5, is a transverse section thereof, taken upon plane of line 5-5, Fig. 4;

Fig. 6, is a transverse section taken upon plane of line 66, Fig. 4;

Fig. 7, is a longitudinal section thereof, taken upon plane of line7--7, Fig. '5;

Fig. 8, is a view similar to Fig. 4, showing a modification;

i ig; 9, is a test lens mount such as is used in connection with my device. a I

In the drawings B, represents a base plate,

referably of annular form, in any case ormed with a circular opening on the inner annular edge 6, on which is mounted the gear ring G, for which purpose said gear G,

may be formed with an inturned flange 5',

which straddles said annular inner edge t, of the base plate B, as shown in Fig. 3.

The gear ring G, carries on its outer or face side a bearing post 9, and also a spring post 9 to which latter the fixed ends of the test lens retaining springs g 9 are secured,-the free ends of said test lens retaining springs g 9 being formed with inturned curved lips g, 9 which are positinned, approximately, diametrically opposite to the bearing post g. As a matter of fact the bearing post g, spring post 9 and retaining lips g, g, occupy relatively slightly more than one-half of the circumference of the gear ring G,-the spring post 9 being situated medially between the bearing post g, and said retaining lips 9*. Hence the rim t, of an ordinary test lens T, such as shown in Fig. 9, may be positioned and held between these three points g, g, and gfl-the spring 9 against which the rim rests tending constantly to press said rim against the two aforesaid posts 9', g, thereby sustaining the test lens in position in alinement with the sight opening in the base plate B. Adjacent to the front of the annular inner edge 6, of the base plate is a degree scale, the 0 mark being in alinement with the stem p, of the pinion p, by which the gear wheel G, is rotated. (See Fig. 3.)

As thus far described the device is practically thesame as one of the duplicate side members of anoculists trial frame, so called, such as used in testing eyesight,-the novelty inthe present case consisting in providing upon the base plate B, a pluralit of adjustable clamps c, 0, by means of w ich an eye-glass, or a portion of one, may be held temporarily in proper alinement with the sight opening in the base plate B, in such manner that its focal value or register may be ascertained by means of trial lenses inserted between the posts g, g*, and retaining springs g ,'on the gear rin G,-the test being continued therewith until a trial lens, or a combination of trial lenses, is found by which the focal effects of the eye-glass are matched and neutralized. Thus, the longitudinal axis of the eye-glass, or portion thereof under observation, being set in alpproximate alinement with the 0 mark on t scale on the front of the base plate, and the trial lenses being in like manner set and read with relation thereto, it is obvious that a when the proper lens, or combination of lenses, is found the denomination number or numbers thereof, taken in connection with the scale reading, Will give the focal re.- quirements and peculiarities of the eye-glass examined in essentially the same manner in which a; like result would be attained by the testing of the eye itselzfi Helium if an orig? nal prescription is lost or not available it may readily be duplicated from eye-glass,

or portion thereoili if broken, and the trouble,

delay, expense; and inconvenience of another eye-test or examination obviated.

it is obvious in this connection that the adjustment of the eyeeglassclaizmps c, 0, may be effected by resort to various Well known mechanical eXpediients,.se-tha1t I (lo-not limit myself in this respect, the clamps and the mounting. thereof shown in the accompanydmawings. indicating the principleinvolved,thedistinctive feature oi my invention being the provision of suitable clamping means wherebyan eyeslensor pertion thereof, may be mounted rigidly on the. base plate B, in" proper relation tothe sight opening therein to bring: it into openative aliinement with; a test lens or. lenses mountedon rotatable gear ring G, in the manner usual in testing eyesight.

any plan-al 025 these eye-lens clamps 0,. may be provided], and at least. three of them are: desirable, I have in. the draw-- ings shown the use of four, each pivotaalily attached to the inner end of its own adjustable rod: or went 0. These clamp: rods e", are mounted on standards 12, on the back of the base plate 15,. in such manner that while: nwipabile"v of longitudinal adjustment thereon they cannot turn latere lly on their longitudinal axes. The simplest way to efiect this result. (although it might obviously be. don-e by spinning) to flatten each; rod. on: one or more sides and topass it through a correspondingly shaped slot or recess 5 in: its. standard 6, as shown by Way of: illustnmtcion in Fig. 651 Intheimodi ficatiomshown iincFi'g, 8,2; 0",an in cross section: is slidable a conrespnnd ingly' shaped socket in the standard: 5: and in desired position by a set. screw 0?. In the other views the clamprods-e, we screw threaded and? engage with. correspondingily threaded nutsng-mtatablee on. the standards. 6}. to) which they are cenneeted by means at flanges e fitting between shoulders b, on, the standards: andlthle members ofitlte-latflsr through which the clamp rodeo, project as pneviously stated.

The clmp jaws 0, being pivotally mounted on the inner ends of their adjustable rods or stems c, readily adapt themselves to any curvature or irregularity of edge of the eye-glass, or portion thereof, 6, placed be tween them, and are held firmly in contact therewith by means of the nut n, o'rs'e't screw '6 as the-case may be.

What I claim as my invention and desire to secure by Letters Patent is,

ll. A focal testing device of the character designated, comprising a base plate formed with a sight opening," atest lens holder r'otatzubly mounted on said base plate and a plumality of independently adjustable pivot'ed clamping jaws supported from said base plate and disposed radially for rigidly supporting an eye lens or portion thereof.

2. A focal testing device of the character designated, emprising a base plate formed with a sight opening, a test lens holder rotatably mounted on said base plate and a plurality of independently adjustable pivoted clan'ipin g: jaws supported from said base plate and disposed radially 03? rigidly supporting an eye lens or portion thereof aliinement with said sight opening.

3. focal testing device'- ef the: character designated, comprising a base plate fiomned with a sight opening, a test lens holder rotatabl-y mounted? on said base plate, stems radially adjustable said base plate, and clamping jaws pivotally mounted on said stems for rigidly supporting eye lens or portion: thereof.

4. A focal testing: device of the character designated comprising a base plate formed with a sight opening, a test lens holder rotatably mounted on said base plate, stems radially adjustable in said baseplate, clamp ing'jaws pivotally' mounted on said; stems for rigidly supporting an eye lens or portion thereof, and at scale on said base plate readable with relation tousaitil rotatable test lensholder.

5. A focal testing device ofthe ehama/eter designated, comprising a base plate formed with m sight-opening, a lens holder rotatably mounted on said base plate; radially disposed stems ad justably carried: by said base plate and clamps pivotallymounted on said stems and means for holding each of said stems ently oFthe-others;

Witnesses-:-

DBROTHT Mam, GED: Wu. Mm.

owed-nones- Oqdn; ofithmpatufllaw he obtained IMIM amt: club, by uddlrudngtheflonm o: Natl,

wtdflngton, D. 0.

adjiisted positions independ- 

